What will happen to life on Earth when the Andromeda and Milky Way galaxies collide?
It is said that the Andromeda and Milky Way galaxies are coming close to each other with a speed of approximately 400000 km/hour. They will be together in the next 4 billion years.
- What will happen to life on Earth or human beings on Earth?
- If we are about to collide in the next 4 billion years then how long before we should take action for interstellar voyage?
- Are scientists working on such projects for an interstellar voyage?
- Will we be able to get the something like Earth to go away from this galaxy/Earth/ solar system and, considering speed of human instruments/spaceships, how long will it take to go to a safe place?
Apart from all the scientific reasons mentioned, we will get an amazing view. It will be fun to witness them collide, at least before the shock reaches us, and if you're planning to live that long.
Why do you assume that any humans or even any observing life forms will be around on Earth in 4billion years?
If "We" humans are still around on Earth in 4 billion years - no small trick, we'd need to move or shield the planet or terraform Mars, but lets pretend we are. The collision with Andromeda might be wonderful thing, many more stars and much greater stellar movement will make inter-stellar travel easier. The galactic collision might be very good, replenishing the galaxy with new star formation and increasing the number of stars passing not too many light years away. Not harmful but wonderful (assuming we're still here in 4 billion years, and assuming no hostile aliens. :-)
What will happen to life on earth or human beings on earth?
Assuming that human beings, or life, still exists on Earth at that time, they will have survived so much due to the ongoing death of the sun, that the gravitational pertubations due to the galactic collision will be nothing.
Keep in mind that in about 1-2 billion years, the sun will be so hot and large that all the water will have boiled off the earth into space. About 3 billion years from now, the surface of the Earth will be so hot that metals will be melting.
Any life that has survived those events and still lives on Earth will surely take a galactic collision in stride.
I imagine, though, that most humans will have fled Earth - if not for distant star systems, then at least for planets in our own system that are going to be warming up enough for human habitation.
If we are about to collide in next 4 billion year then how long before we should take action for inter-stellar voyage?
As soon as possible. When interstellar voyage becomes possible, we should start sending out ships to colonize other planets and star systems. This will likely take a long time, but if we are to survive more than a billion years, it is necessary. Keep in mind that the Sun and Andromeda are events we can predict. We don't know, and can't predict, the next cataclysmic asteroid strike, which is likely to happen in a shorter time than a billion years. There are lots of reasons to exit the planet, we should be worried about the ones we can't predict or see, not the ones we can predict.
Are scientists working on such projects for inter-stellar voyage?
Yes, but in small steps. Manned missions to space, to the moon, and living aboard the ISS have provided significantly valuable information that will be used in such interstellar missions. As we continue to push the boundaries of our ability to survive in space we eventually will be able to live in space, perhaps whole lifetimes will be spent in space. As engine technology progresses beyond simply lifting people out of Earth's gravitational well, we will eventually be sending people on long voyages outside our solar system.
It's a very, very long way off, but each advance takes us closer to that eventual goal.
I'm hoping we'll move Earth to a safe distance by that time, for sentimental reasons if nothing else.
@KeithThompson It'll be a brownfield site by then, a dead bird hanging around the human race's neck. Might as well let the star ingest it and hope other civilizations that we come across don't find out until after we've stripped their planet(s). ;)
You should provide evidence (via links to respectable sources) for your claims that in 1-2 billion years water on Earth will be evaporated.
@Walter It is fairly well accepted by the scientific community that the Sun's next phase is red giant, with a diameter well beyond the current Earth's orbit. You can do an internet search for "When will the oceans boil away" and choose which source you find most respectable, ignoring, if you like, the global climate change estimates which move the models up a few million years. An interesting recent paper on this subject is "Distant future of Sun and Earth revisited" at http://arxiv.org/abs/0801.4031 *"...it is clear that Earth will come to leave the HZ already in about a billion years time"*
I was not asking for a comment, but for improvement to your answer, and I was not asking because I doubted it, but to give you a chance to improve your answer (though I was a bit surprised at the time scale of only 1Gyr).
I like your optimism about interstellar voyage. I hope you are right, but there is no guarantee that we will ever be able to traverse the distance in a human lifetime. Maybe we could send out an "ark" someday, but if you look at arguments like those presented in Kim Stanley Robinson's book, "Aurora", sustaining such an ark may be a lot harder than people realize. And we have no idea where to go yet. I think our best option will be space colonies that can be relocated to different distances from our star where we can continue to get solar energy and mine resources from moons and asteroids.